Flap valve

ABSTRACT

The specification describes a flap valve with a generally transversely extending flap arranged to be operated by a driving shaft lying outside the passage through which material flows through the valve. The shaft carries a lug fixed on it which extends into the passage and is pivotally connected with the flap near the center of the latter. Rocking of the shaft about its axis causes the flap to be moved towards and away from its seating. In order to ensure that the flap, after being moved clear of its seating, swings into a position perpendicular to its closed position in the passage, a linkage is provided. This linkage comprises two arms and two links. The arms are carried on the shaft and are normally stationary during operation. The links are connected with the arms and the flap. The angular setting of the arms, and hence of the flap can be changed by means of an adjustable stop mounted on the casing.

United States Patent 451 June 13, 1972 [30] Foreign Application Priority Data Feb. 23. 1970 Germany ..P 20 08 359.4

52 US. Cl. .251/279 [51 Int. Cl. ..Fl6lt 31/44 [58] Field Search ..2$ H279, 280, 298; l37/527 [56] Relerences Cited UNITED STATES PATENTS 2,839,082 6/1958 Moore et a] ..251l279 X Primary Examiner-Henry T. Klinltsiek Amman: EXdhll'Mr-DflVid R. Matthews Attorney-Price, Heneveld, Huizenga 8: Cooper ABSTRACT The specification describes a flap valve with a generally transversely extending flap arranged to be operated by a driving shaft lying outside the passage through which material flows through the valve. The shaft carries a lug fixed on it which extends into the passage and is pivotally connected with the flap near the center of the latter. Rocking oi the shaft about its axis causes the flap to be moved towards and away from its seating. In order to ensure that the flap, after being moved clear of its seating, swings into a position perpendicular to its closed position in the passage, a linkage is provided. This linkage comprises two arms and two links. The arms are carried on the shaft and are nomially stationary during operation. The links are connected with the arms and the flap. The angular setting of the arms, and hence of the flap can be changed by means of an adjustable stop mounted on the casing.

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PATENTEDJUR13 m2 3.669.405

sum 1 or 2 INVENTOR ATTORNEYS PATENTEDJUN 13 m2 sum 2 OF 2 INVENTOR ATTORNE YS FLAP VALVE BACKGROUND OF INVENTION 1 Field to which invention relates The present invention relates to flap valves, and more par ticularly to such valves in which the flap is moved away from its seating for opening while remaining approximately parallel to itself for a short distance and is then swung into a position, inside the passage of the valve, in which it is approximately perpendicular to its closed position.

2. The prior art In accordance with a previously proposed construction of such flap valve in which the flap was firstly moved axially and then twisted for opening the flap was to be driven by a driving shaft placed substantially outside the passage of the valve casing. The driving shaft was connected with the flap by means of a lug fixed near the center of the flap in a pivoting manner by means of a pin parallel to the shaft. Swinging movement of the flap was to be brought about by means of links arranged on both sides of the lug. Each link was connected at one end pivotally with the casing while the other end was connected pivotally with the flap. In a particular construction in accordance with this prior proposal the links were to be connected pivotally with parts which were integrally cast with the casing or housing or were welded on it. The other ends of the links were to be journalled in fins attached to the flap. The pin forming a pivot for the lug on the flap was also mounted in fins, which extended across the flap so as to be substantially parallel to the lug.

It can be seen that such a construction is comparatively difficult to produce and in particular requires especial care in positioning the bearing openings in the parts fixed to the interior wall of the casing, that is to say by integral casting or welding on.

Furthermore the large number of offset movements parallel to the axes and the necessary guide bearings necessarily leads to departures in the loading of the mechanism and to undesired inaccuracies from the theoretical value owing to manufacturing tolerances. Such defects necessarily lead to leakage through the valve and may also lead to flutter in all positions of the valve flap except for the closed position.

Furthermore the construction in accordance with the prior art does not make it possible to make the flap completely radially symmetrical, so that owing to the unavoidably resulting asymmetrical elastic deformation of the flap it is not possible to achieve an even sealing engagement on all metallic seating surfaces,

SUMMARY OF INVENTION One object of the present invention is to provide a flap valve in which the manufacturing difficulties connected with production of the housing and the flap drive mechanism are substantially reduced and furthermore to make possible a precise setting of the pivot bearings of the links on the housing without difficulties.

A further object of the invention is to provide such a flap valve in which the flap can be made radially symmetrical, so that an even sealing action is guaranteed along its whole periphery in every application.

The present invention consists in a valve comprising a casing defining a passage for the flow of material, a valve seat attached to the casing, a flap extending across the passage for engaging the seat, an operating shaft mounted on the casing substantially outside the passage, a lug which extends from the shaft to the flap is fixed on the shaft and is pivotally connected with the flap near its center, relative rocking movement between the flap and the lug being arranged to take place about an axis parallel to the shaft, at least one link, link anchoring means, the link being pivotally connected with the flap and the anchoring means for causing the rocking movement of the flap in relation to the lug when the lug is turned by the shaft, characterized by the provision of at least one arm, constituting the anchoring means, mounted on the shafi, and

means for checking rocking movement of the arm in relation to the casing about the axis of the shaft, the arm extending towards the center of the flap from the casing.

In accordance with a preferred feature of the invention there are two such arms and two such links and the arms are connected with the shafi by means of sleeves in which the shaft can rotate. Furthermore the arms are provided with projections which are arranged to engage stop means on the housrng.

With this construction it can be seen that it is possible to arrange for the arms, which were previously joumalled eccentrically, to extend into the center of the arrangement and thus provide a more convenient connection with the flap. Conveniently the flap can be provided with the center piece with a projection for pivotal connection with the lug and with the levers respectively.

The central arrangement of the lug and the links on the flap makes possible a radially symmetrical construction of the flap and thus makes possible an even sealing action along the periphery of the flap.

With the construction in accordance with the invention it is also possible to bring about a substantial improvement in the pivot bearings for the links. Since the arms in accordance with the invention are provided with projections or extensions, which engage stop means on the housing, it is possible, in accordance with a further feature of the invention, to provide for vertical adjustability of the stop means so that these arms and the sleeves mounted on them on the shaft can be brought into the correct aligned position in relation to each other in the valve casing or housing. Accordingly manufacturing tolerances can be completely overcome by a simple subsequent adjustment of the stop means.

Owing to the radially symmetrical construction of the flap and the arrangement of the pivot points or bearings for the lug and the links in a separate part which is mounted on the flap precisely centrally any elastic deformations which may occur are also radially symmetrical so that an even closure of the flap valve is ensured. Furthermore the central attachment of the lug and the links on a center piece provided for these purposes substantially reduces the manufacturing in costs of the valve flap which, before the center piece is mounted on it, is substantially smooth in outline.

LIST OF SEVERAL VIEWS OF DRAWINGS One embodiment of a flap valve in accordance with the invention is now described with reference to the accompanying drawings.

FIG. I represents a section along the line II of FIG. 2.

FIG. 2 represents a section along the line IIII of FIG. 1.

DESCRIPTION OF PREFERRED EMBODIMENTS In the figures reference numeral 1 denotes a housing or casing, which at its ends carries welded-on flanges 2, 3, which can be connected with pipes in a pipe line which is to be controlled by the flap valve.

In the casing 1 there is a seating ring 4 in which a seating part 5 is mounted against which the flap 6 rests with its periphery when the valve is closed. In the embodiment shown the flap is an integral construction which in its center part carries a hollow boss 7, on to which a cover plate 8 is screwed. The cover plate carries an extension 9 for carrying the two bearings 10 and I] for the lug l2 and the links 13 and 14. The lug 12 is made u of two parallel limbs in the embodiment shown, as can be seen more particularly from FIG. 1.

The extension 9, 9a is made up of two parallel limbs as is shown by FIG. 1. Between the two limbs of the extension 9, there is the ivot bearing 10 for the lug 12, while on the end of the limbs of the extension 9, 9a remote from the flap 6 there are pivot bearings II for the links 13 and I4. As can be seen from the section of FIG. 2 the housing 1 is provided on its top side with a shroud 15 in which two sleeves l6, I? are welded on to the casing l.

These two sleeves accommodate the operating shaft 18 which has a free end connected with a drive mechanism for swinging the shaft about its axis. On the shaft 19 there is a sleeve 20 which is connected with the shah 18 by means of a key 21 to prevent relative rotation between them. The sleeve 20 carries the two limbs of the lug 12 so that on rotation of the shaft 18 about its axis the sleeve 20 also rocked so that the lever or lug 12 can be swung with the flap 6 mounted on it.

The links 13 and 14 pivoted in the pivot bearings 11 are, in the embodiment shown, connected at their other ends with arms 22 and 23 which are fixed on sleeves 24, 25. The sleeves are journalled on the shaft 18. Also the sleeves 24, 25 can be turned in the sleeves l7 and 16 but their position in relation to the housing or casing, and therefore also the position of the arms 22 and 23 in relation to the casing is fixed by a stop 26, which is mounted in a sleeve 27 fixed on U18 casing. The stop can be set by means of the setting screw 28 so that by suitable operation of the two setting screws 28 for the two arms 22 and 23 with their extensions engaging the stops can be aligned without difficulty together with their pins 29 and 30, which provide pivotal connections with the links 13 and 14. The course of movement of the flap 6 is indicated in FIG. 2 which for this purpose shows the end position of the flap in broken lines.

I claim:

1. In a valve comprising a casing defining a passage for the flow of material, a valve seat attached to the casing, a flap extending across the passage for engaging the seat, an operating shaft mounted on the casing substantially outside the passage,

a lug which extends from the shah to the flap, is fixed on the shaft and is pivotally connected with the flap near its center. relative rocking movement between the flap and the lug being arranged to take place about an axis parallel to the shaft, at least one link, link anchoring means, the link being pivotally connected with the flap and the anchoring means for causing the rocking movement of the flap in relation to the lug when the lug is turned by the shaft. the improvement which resides in the provision of at least one arm, constituting the anchoring means, mounted on the shaft, and means for checking rocking movements of the arm in relation to the casing about the axis of the shaft. the arm extending towards the center of the flap from the casing.

2. The structure as set forth in claim 1 comprising two such arms and two such links.

3. The structure as set forth in claim 1 comprising at least one sleeve rotatably mounted on the shaft and carrying the arm.

4. The structure as set forth in claim 1 in which the movement checking means comprises an extension on the arm and a stop on the casing for abutment on the extension.

5. The structure as set forth in claim 4 in which the stop can be moved towards and away from the axis of the passage for adjustment.

6. The structure as set forth in claim I comprising a center piece extension mounted on the flap and pivotally connected with the lug and the link. 

1. In a valve comprising a casing defining a passage for the flow of material, a valve seat attached to the casing, a flap extending across the passage for engaging the seat, an operating shaft mounted on the casing substantially outside the passage, a lug which extends from the shaft to the flap, is fixed on the shaft and is pivotally connected with the flap near its center, relative rocking movement between the flap and the lug being arranged to take place about an axis parallel to the shaft, at least one link, link anchoring means, the link being pivotally connected with the flap and the anchoring means for causing the rocking movement of the flap in relation to the lug when the lug is turned by the shaft, the improvement which resides in the provision of at least one arm, constituting the anchoring means, mounted on the shaft, and means for checking rocking movements of the arm in relation to the casing about the axis of the shaft, the arm extending towards the center of the flap from the casing.
 2. The structure as set forth in claim 1 comprising two such arms and two such links.
 3. The structure as set forth in claim 1 comprising at least one sleeve rotatably mounted on the shaft and carrying the arm.
 4. The structure as set forth in claim 1 in which the movement checking means comprises an extension on the arm and a stop On the casing for abutment on the extension.
 5. The structure as set forth in claim 4 in which the stop can be moved towards and away from the axis of the passage for adjustment.
 6. The structure as set forth in claim 1 comprising a center piece extension mounted on the flap and pivotally connected with the lug and the link. 